var x1 >= .5 <= 5.8   := 0.9;
var x2 >= -2.9 <= 2.9 := 1.1;
minimize f: (x1 - 1)^2 + (x2 - 1)^4;
s.t. g1: x1^2 <= x2/2;
s.t. g2: x2^2 <= x1/2;
